Hydraulic brake control mechanism



n Patented July 11, 1944 HYDRAULIC BRAKE CONTROL MECHANISM CharleyLaurence Green, Corpus Christi, Tex.,

asslgnor of one-third to 0. W. Schroeder, Corpus Christl, Tex.

Application March 11, 1942, Serial No. 434,284

- 1 Claim.

This invention relates to certain new and useful improvements in brakecontrol mechanisms as applied to iiuid actuated brakes on wheeledvehicles.

The advantages of my invention over similar devices now in use consistsof a simpliiied construction and a quicker and more positive brakingpressure and an automatic cutout for any broken or defective linesleading to the brakes.

An important object of the invention is to provide signalling meansassociated with the brake-actuating mechanism to warn the driver of adefect therein.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter describedand claimed, referencebeing had to the accompanying drawing forming part hereof, wherein likereference numerals refer to like parts throughout, and in which- Figure1 is a plan view of the mechanism. showing it attached to the frame of afourwheeled vehicle. l

Figure 2 is a vertical section showing the operating parts on thedevice, and

Figure 3- is a fragmentary sectional view taken on the line 3--3 ofFigure 2. Y

This speciiication, with the accompanying drawing, wherein likereference numerals refer to like parts throughout, fully describes theinvention.

Numeral I is the frame of a typical vehicle on which is mounted the body2I of the control mechanism. The body 2 contains a multiplicity ofcylinders, 3 and 4, in which travel the brakeactuating pistons 5 and 8,which are connected by means of the rods 1 and! tothe crosshead 9, soarranged that when the operating pedal I is depressed, equal pressure isapplied to the pistons and 6. The pistons 5 and 6, when completing theiractive stroke, are returned to position by the springsv I0. Liquid inthe cylinders 3 and 4 is forced by the movement of the pistons 5 and 5through the openings II and I2 into the transverse cylinder Il, in whichtravels the floating piston I4, which is normally balanced in a medialposition by the springs I5 and I5. The ends of the cylinder I3 aretightly closed by the screw plugs Il. The discharge of the cylinders isthrough the tubes I8 and I9, each leading to the independently actuatedrear and front hydraulic brakes 2n and 2l; The brakes are of the usualpiston-operated type.

A liquid receptacle or chamber 22 is provided directly over thecylinders 3 and 4 and is kept constantly full of operating liquid to theexclusion of air by means of the filling plug 23.

Ports 24 and 25 provide communication between the liquid receptacle 22and the cylinders 3 and Y4, and the iirst movement of pistons 5 and 5,put into action through the piston rods 1, by means of pressure on the`foot pedal, is to close the said ports 24 and 25, thus insuring that thecylinders 3 and 4 are keptconstantly filled with liquid.

The receptacle 22 is divided by a web or partition extending full lengthof the receptacle and from bottom to within one-fourth inch of the cover2, thus preventing drainage of both cylinders 3 and 4, should eitherpiston 5 or 6, or line I8 or I9 become defective. This partition is soconstructed that it will not interfere with the filling of thereceptacle.

Ports 26 are for return of liquid that might have been forced behind thepistons 5 and 6, also providing a softening of the back slap of pistonsand pedal assembly.

The wearing surfaces of the cylinders 3 and 4 are protected fromabrasion from dust by the rubber packing 32.

Normally, while the braking system is at rest, ports 24 and 25 willinsure free ow oi' lling fluid to cylinders 3 and 4. Should the pressureon one cylinder be slightly greater than on the other, the pressurewould be equalized by the action of the floating piston I4.

Mounted in each plug I1 is a contact 29 projecting into the cylinder I3and normally spaced from the piston I4 by the springs I5 and I6. Circuitwires 30 lead to a suitable signal device adjacent the driver (notshown).

Should a, leak occur in part of the braking system, for example thatpart controlled through thetube I8, the lessened pressure in cylinder 4and the continued pressure in cylinder 3 applied through port. I2 to theequalizing piston I4 will move piston I4 into contact with contact 29.This action flashes a warning light on the instrument panel of thevehicle, showing the braking mechanism 5 and I8 to be at fault. Whenthis happens, all of the braking power will bey exerted upon thatportion of the brakes operated through the tube I9. y

Thus, any leak in the braking system causing a loss of pressure andbraking power can only effect that part of the braking system fed by onecylinder.

Having thus fully described my invention I claim:

A brake-operating control mechanism for fluid pressure braking systemscompri-sing a. plurality of cylinders, a fluid filled chamber havingcontrolled connections to the cylinders, brake pedalactuatecl pistonsadapted to apply pressure to the fluid contained therein, a transversecylinder having communication with the rst-narned cylinder, and havingbrake lines leading therefrom adjacent the outer ends thereof, abalanced pressure-operated piston in the last-named cylinder adapted tobalance the pressure in the brake lines, a partition in the chamber of aheight less than the height of the walls of the chamber to provide freecommunication throughout the chamber when the same is filled with liquidand limiting ow of liquid to the respective cylinders connected with thechamber when liquid in the chamber at either end of the partition dropsbelow the level of the upper edge of the partition, an electric contactin each end of the transverse cylinder and disposed in the path o!movement of the opposite ends of the last named piston for engagementthereby upon a. predetermined movement of such said last named piston,said contacts being included in an electric circuit with a signallingdevice, and said last named piston closing one of the brake linesleading from the transverse cylinder when moved in either direction intoa position for engaging an adjacent contact.

CHARLEY LAURENCE GREENl

